Wireless communication systems have become an important means by which many people worldwide have come to communicate. A wireless communication system may provide communication for a number of mobile stations, each of which may be serviced by a base station.
The 3rd Generation Partnership Project, also referred to as “3GPP,” is a collaboration agreement that aims to define globally applicable technical specifications and technical reports for third generation wireless communication systems. The 3GPP may define specifications for the next generation mobile networks, systems, and devices. In 3GPP specifications, a mobile station is typically referred to as a user equipment (UE), and a base station is typically referred to as a Node B or an evolved Node B (eNB).
3GPP Long Term Evolution (LTE) is the name given to a project to improve the Universal Mobile Telecommunications System (UMTS) mobile phone or device standard to cope with future requirements. In one aspect, UMTS has been modified to provide support and specification for the Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN). LTE-Advanced is the next generation of LTE.
In LTE release 8, the PUSCH (Physical Uplink Shared Channel) supports only one transmission mode, i.e., one antenna mode. But in LTE-Advanced, the 3GPP is attempting to specify several transmission modes, i.e., T×D (transmit diversity), SU-MIMO (single user-MIMO) and MU-MIMO (multi-user-MIMO) for PUSCH. Supporting SU-MIMO in LTE-Advanced means that at least some UEs have to support two power amplifiers.